Water that can last year-round

Children and a donkey walking on a sand dam. -AP

ON a dry riverbed one recent sunny morning, residents of Kasengela village toiled away mixing cement and sand to make concrete. The sound of their shovels resonated through the valley while other residents, working in pairs, carried rocks to the site in wooden frames.

They were building a sand dam, a structure for harvesting water from seasonal rivers. The barrier, typically made of concrete, impedes water flow and coarse grains of sand settle behind it, creating an artificial aquifer that fills up during rainy seasons.